Pi Definition and 514 Threads

  1. J

    Why is pi = 16 arctan(1/5) - 4 arctan( 1/139)

    Not actually a HW question, but, is there a quick explanation that could show why: \pi = 16\arctan(\frac{1}{5}) - 4\arctan(\frac{1}{239}) I read that somewhere, and it turned out to be true, so I was just wondering how that came about...
  2. L

    Non integer square roots and pi = irrational?

    Since one can construct the length of a non-integer square root by drawing accurate triangles, and can draw a circle with a circumference of pi, then shouldn't one be able to plot corresponding non-integer square roots and pi on a number line? I know these numbers are supposedly irrational, but...
  3. L

    Gamma Function, Gamma 1/2=root pi

    Hiya, I'm having trouble finding a simple proof for gamma of 1/2 = root pi? Any suggestions
  4. L

    QM- Tiny question on sigma & pi bonding states

    Could somebody please explain the 2-fold degenerate sigma 2p is lower in energy than that of 4-fold degenerate the pi 2p bondings state in the O2 molecule? Does it have anything to do with resonance energies perhaps?
  5. J

    Where does the pi come from in the sum of inverse squares?

    I saw the other thread, but figured this question was sufficiently distinct to warrent a new thread I was recently looking at this series \[ \sum_{n=1}^\infty \frac{1}{n^{2}} = 1 + \frac{1}{4} + \frac{1}{9} + \frac{1}{16} + \cdots + \frac{1}{n^{2}} = \frac{\pi^{2}}{6} \approx 1.645 \] My...
  6. V

    How Did Mathematicians Discover the Value of Pi?

    How was the irrational number pi invented or how did man reach upon it? I have studied elementary calculus to understand the basic kinematics. In fact I know only the formulae to find for integration and derivative of some standard functions. The limits and such things weren't taught to me. It...
  7. A

    What is the Exact Number to Pi?

    Pi does anyone know the exact number to pi (yes the one over 1000 characters long:P) i need it a.s.a.p
  8. V

    Can Pi be Constructed on a Number Line Using Non-Traditional Tools?

    how to plot the irrational number pi on a number line. i know the procedure for square roots of different non-perfecr square number. it is by drawing a perpendicular at a suitable integral length again at suitable integral length such that the hypotenuse is of required length as per the...
  9. E

    Remebering pi Going beyond remembering 3.14

    I recently though it would be kewl to remember pi up to 256 digits :rolleyes: Ok, I am a little wacko. My original idea was to remember 1 digit per day. But in the last three days, I have already memorized the first 18 digits. I couldn't help but look. In any event, what would be the...
  10. B

    Drawing a Feynman Diagram for K^{*+}→K^0 + \pi^+

    Hi I have to draw a Feynman diagram for the following reaction: K^{*+} \rightarrow K^0 + \pi^+ The K^{*+}-meson is composed of an u and an anti-s quark, the K^0-meson is composed of a d and an anti-s quark, and the \pi^+-meson is composed of an u and an anti-d quark. I have drawn...
  11. M

    Maple How to use the function pi in maple

    Maple Help! could anyone tell me how to use the function pi in maple. http://en.wikipedia.org/math/e66964312bccf80023e4815edd53a542.png i need to figure it out for a statistical mechanics assignment. Thanks
  12. J

    Did the movie Pi really have a government conspiracy involving brain implants?

    Has anyone ever seen this movie? It really is not all that great, and in one scene the main character, which is a mathmatician, is describing the number phi and the logarithmic spiral, but for some reason he calls it theta instead of phi. I don't know if that is completely incorrect, or if...
  13. quasar987

    Developping sin(x) on [0, pi] as a serie of cosines

    Am I crazy or this is impossible to do if we require that the period of the extended even function be 2pi ? Yet, this question comes in my textbook before the section concerning Fourier extension of functions of period other than 2pi. So there must be a way?
  14. P

    Are the digits of pi truly random?

    My son's computer science teacher claims that there is no way to devise a computer algorithm that can generate a truly random sequence of numbers (only a pseudo-random sequence that ultimately repeats). Yet there are algorithms with a finite number of steps that generate the decimal digits of...
  15. A

    Pi in Base 16 - special formula

    About 20 years ago I caught an article about a graduate student who had found an algoritm which would return the n-th digit of \pi without needing to compute the preceding digits. In other words you could ask for the 812th digit of \pi and it would spit it out without computing the...
  16. B

    Name for 1/(4πε₀)? What is the Meaning?

    Has a name been given to this constant? The most I've seen is calling it k, but is there another name for it, or any statement for understanding its meaning (such as how e0 can be called the "permittivity of vacuum")?
  17. Y

    Can the digits of Pi be used to predict the future?

    almost everyone has heard of the Bible code. what about the pi code? predicting the future with the Pi code! infinite digits means all possible combinations, right? if you get bored one day, you can predict the future.
  18. BobG

    Celebrate Pi Approximation Day 22/7

    It's a happy day :biggrin: Today is pi approximation day. The date, written in day/month format, is 22/7. I doubt the celebration will be quite as extravagant as the pi day of 1592 - March 14, 1592 at 6:53:58 (3/14/1592 6:53:58) touched off one the great celebrations in man's history. I...
  19. Math Is Hard

    Public Service Announcement: It's PI, Not PIE!

    OK, I can't stand it any more. This is a Public Service Announcement. The ratio of the circumference of a circle to its diameter is called pi, not pie. OK, here's a small demonstration just to clarify: This is pi: http://www.ualr.edu/~lasmoller/mathresources/bigpi.gif This is pie...
  20. DaveC426913

    Pi and Curved Spaces - Is it Constant?

    pi is the ratio of circumference to diameter.That is true in a flat, Cartesian space. In a curved space, a physicist measuring the ratio of the circumference of a circle to its diameter will come up with a different value, which will be more or less than pi depending on which way his space is...
  21. JamesU

    Pi is said to be discovered by ancients

    Pi is said to be discovered by ancients, but if even we don't know the EXACT number of pi, how could they, or was theirs just a close estimate of pi?
  22. G

    Can You Prove ln(e)/e > ln(pi)/pi Without Calculations?

    I haven't been able to prove: ln(e)/e > ln(pi)/pi without calculating any of the values. Help would be much appreciated.
  23. Y

    How many pi bonds are present in sp^3, sp^2, and sp hybridizations?

    pi bonds for hybridizations, yes/no questions im having a bit if trouble with this but i need to know the number of pi bonds for the sp^3, sp^2 and sp hybridizations thanks if you can help ^^ i have another question as well,there are some questions and they have yes or no answers but I'm...
  24. E

    Proving the Relationship Between Integrals and Root Pi Using Multiple Integrals

    A problem in my textbook guides you through this proof using a multiple integral. I follow the whole thing except for one step. It requires that you show that (sorry don't know latex, I(a,b) will denote integral from a to b, e the exponential) [I(-x,x)e^(-u^2)du]^2=I(R)e^(-u^2-v^2)dudv...
  25. K

    Calculating PI with Different Methods - KMCB1234

    In what way can i calculate PI and output the result to the screen ? I heard from my friedn that MC method is good but is there any other ways to do that ? also, how many decimal digits am I able to output the result ? Thank you in advance -KMCB1234
  26. D

    Approximating Pi and e with Linear Algebra

    I was wondering if there are any formulations of Pi or e that use "n-euclid space" to approximate it? Or really just the use of any linear algebra to approximate Pi or e? Thanks... Derek Mohammed
  27. C

    Is Pi the Most Precise Number in Existence?

    How do we know pi to so many decimal places? How can that be determined so precisely? http://wikisource.org/wiki/Pi_to_1%2C250%2C000_places
  28. I

    Why do fractals and Pi have a special relationship?

    This was brought to my attention today, and I haven't had much time to think about it; I think it has something to do with fractals. If you have half a circle with diameter of 2, the circumference will be \pi. If you create two circles, each with diameter of 1, the combined length of the...
  29. Integral

    Can you use a mnemonic to remember Pi?

    How I need a drink, alcoholic of course, after the heavy lectures involving quantum mechanics. All of thy geometry, Herr Planck, is fairly hard
  30. A

    Solving for Cotangent using Cosine and Pi

    \cos \theta = \frac {2} {3} and \frac {3\pi} {2} <\theta<2\pi then determine the exact value of \frac {1} {\cot\theta} I did this question using sin^2+cos^2=1 subbing in cos and then solving for sin when i got both values i realized that 1/cot theta = tan theta which is (sin theta)/(cos...
  31. B

    What Does the Tall Pi Symbol Mean?

    does anyone know what the symbol that looks like a tall pi means?
  32. C

    Understanding the Hybridization and Formation of Pi Bonds in Ammonia and Ethyne

    In ammonia, why the N atom is sp3 hybridized and not sp2 hybridized...since there are only 3 bondings... Also, in ethyne, that is H-C(triple bond)C-H...for the formation of 2 pi bonds, why it is the unhybridized 2px orbital and 2py orbital of each C atom overlap with each other? How about the...
  33. F

    Is Pi Truly Random and Continually Digited in its Calculation?

    If Pi is continual and random-digited as scientists say, then how could it be the quoteint of the circumference and the diameter, because any thing that includes a fraction cannot be continual and random digited. The only explanation that keeps Pi continual and random digited is that the...
  34. arivero

    Exploring Pi Square Lads: Latest Developments in Integer Pythagorean Triples

    Lads, I'd be glad if you were able to take a view of the last developments in the thread https://www.physicsforums.com/showthread.php?t=46055 and see if you can do some suggestion, as we have a pi^2 expresion which should somehow be related to integer pythagorean triples.
  35. Z

    New Number System Allows Pi to be Exact

    Pi can be exact if we have a new number system. :mad:
  36. F

    Pi doesnt have reapting random digits

    Supposedly Pi has infinite and random digits. Therefore pi cannot be a fraction unless the top numeber or the bottom number is a number with infinite and reapiting random digits. so therefore the diameter or the circumference must always be a infinite and random digited. BUT, this isn't true. if...
  37. arivero

    All the lepton masses from G, pi, e

    Plus c and h, of course. The idea is to collect here in only a thread all the approximations voiced out during the summer. Surely this is to be quarantinised in TheoryDev, but it is interesting enough to be kept open as a thread (if closed, please be free to use my...
  38. N

    PI: More mokeys with Typewriters?

    PI: More mokeys with Typewriters!? There exists a recent post on the subject of an infinite amount of monkeys doing a lot of typing. You know the premise. I was going to post this there, but figured it might deserve to be a new thread altogether. There's this number- Pi: 3.14159... and off...
  39. I

    What is the significance of the relationship between phi and pi?

    This is by far the most exciting site on pi and phi I have ever seen. You must see this. http://goldennumber.net/five(5).htm Don't forget to see the side links to other pages in the site that describe other interesting facts.
  40. M

    Accuracy of Pi: Arguing with Dad

    My dad and I got in an argument about accuracy of pi values. He said that the ratio 22/7 will always be more accurate than any decimal value of pi. I said that the value 3.14159265358979 is much more accurate. I'm 100% certain that I am correct, but I can't really think of how to prove this...
  41. C

    How Does the Buckingham Pi Theorem Apply to Homogeneous Functions in Physics?

    This is more of a dimensional analysis or unit analysis problem than a basic analysis problem. So if I didn't post this thread in the right forum, please delete it. Moving on, I'm having trouble grasping the concepts behind the Buckingham Pi Theorem. After reading some textbooks and doing...
  42. D

    C/C++ How would I go about defining pi in C++?

    How would I go about defining pi (and using) as 3.1415926535897932384626433832795? I've tried using double, long double and #define pi 3.1415926535897932384626433832795 but it, instead, takes 3.14159. Is there any way to get it more accurate?
  43. M

    Pi miscalculated or not irrational?

    pi miscalculated or not irrational? I know that computers have calculated thousands of digits of pi, but does this mean that pi is an irrational number? How can we be so sure that it is irrational? And I have one more question. The circles we see in real life are not perfect circles. Does this...
  44. L

    Proofs on the rationality of pi

    Im looking for some proofs on the rationality of pi. I also want to know what some people think about it.
  45. shintashi

    The reversed Cicular Pi !Reversed Circular Pi: A New Math for Geometric Shapes

    :smile: Hi ! I was pondering over the morphology of etymology, and the tonal "Aum" or "OM" of the vedic sanskrit. If you look at these tones in a cymatic (wave theory) way, you discover some unqiue principles. All of our time we have spent trying to create pi...
  46. I

    Square Root of Pi: Is it Possible?

    The square root of pi is 1.777245... I know. But my math teacher says its impossible to determine a square root of an irrational number. Can anyone shed any light on this? is it or is it not possible to determine the square root (or any root) of an irrational number?
  47. D

    Uncovering the Origins of Pi: A Closer Look at Archimedes' Approximation

    what does pi mean, and where did it come from, i know its 3.141592654, but i also know there's a lot more decimal places then that, does anyone know anything about it?
  48. E

    Calculating Mean Distance Traveled by Pi-Mesons at Speed v=0.3c

    A beam of charged pi-mesons is traveling with a speed of v=0.3c. The mean life of a pi-meson is 2.6 x 10^-8s. What is the mean distance traveled by a pi meson before it decays? How do u do this?
  49. F

    Is Pi Actually Transcendental?

    is this correct -(pi) + (1 - 2i)((pi)^2) = i^2 i = (-1)^(1/2) (pi)= 3.142... peace :redface:
  50. T

    Why Is Pi Fascinating in Science and Mathematics?

    I'm doing this paper on pi and the question popped up in my mind: why is pi interesting to us? ok, it might be interesting to find new, faster ways to calculate it and stuff like that, but does it have any use, function? what progress are we making? I know it's ralated to the strings in the...
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